Since KitKat, only root or an app that owns a folder can write to it, so if you're trying to use one app to write to another app's folder, it won't work. (That's how Linux works and, since KitKat, the card has been considered part of the Linux file system.)

Since KitKat, only root or an app that owns a folder can write to it, so if you're trying to use one app to write to another app's folder, it won't work. (That's how Linux works and, since KitKat, the card has been considered part of the Linux file system.)

That's odd... I can read and write my microSD card just fine with ES File Explorer, no root.

So back to the OPs question... the first thing I would do is reformat the card, if that fail in the cart still shows read only I would try a different card. I have seen a few people mention here and there that the Moto G does not like some older Micro SD card